Memory devices provide data storage for electronic systems. One type of memory is a non-volatile memory known as Flash memory. Flash memory is a type of electrically-erasable programmable read-only memory (EEPROM) that is erased and reprogrammed in blocks. Flash memory is popular in wireless electronic devices because it enables the manufacturer to support new communication protocols as they become standardized, and to provide the ability to remotely upgrade the devices for enhanced features. Not-and (NAND) Flash memory includes at least one selecting device coupled in series to a serial combination of memory cells, with the serial combination being commonly referred to as a NAND string. A conventional NAND memory array includes conductive lines, such as access lines (e.g., wordlines) and data lines (e.g., digit lines, such as bit lines), and memory cells, which are located at intersections of the wordlines and bit lines. The memory cells include a source, a drain, a charge storage structure, and a control gate. Individual memory cells are organized into individually addressable groups, such as bytes or words, which are accessed for read, program, or erase operations through address decoding circuitry using wordlines and bit lines.
In one conventional NAND architecture, contact to the wordlines is made utilizing a so-called “shark jaw” layout. FIGS. 1-3 illustrate the wordlines 2 at various stages of fabrication and of making contact to the wordlines 2. So-called “loops” 4 of conductive material 6 are formed (e.g., printed) by conventional techniques, producing a non-uniform pattern, as shown in FIG. 1. Once the conductive material 6 is opened (e.g., discontinuous), each loop 4 forms two wordlines 2. For ease of illustration, FIGS. 1-3 only illustrate a section of the loop 4 of the wordlines 2. In the non-uniform pattern, the distance “X” between first portions 8, 8 of conductive material 6 is narrower than the distance “Y” between second portions 12, 12 of the adjacent conductive material 6 and the distance “Z” between third portions 10, 10 of the conductive material 6. FIG. 1 illustrates sections of three loops 4, with each loop 4 having substantially parallel and substantially perpendicular portions of conductive material 6. First portions 8, 8 of the conductive material 6 are substantially parallel to one another, third portions 10, 10 of the conductive material 6 are substantially perpendicular to first portions 8, 8 and substantially parallel to one another, and second portions 12, 12 of the conductive material 6 are substantially parallel to one another and substantially perpendicular to third portions 10, 10. The increased distances “Y” and “Z” between the second portions 12, 12 of the conductive material 6 and the third portions 10, 10 of the conductive material 6 are utilized to provide sufficient space for contact landing pads 14 and contacts 16 to be formed, as shown in FIGS. 2 and 3. However, the different spacings (e.g., non-uniformity) between the first portions 8, 8, the second portions 12, 12, and third portions 10, 10 of the loops 4 cause difficulties in photolithography acts utilized to form the loops 4. Before forming the contact landing pads 14 and contacts 16, the loops 4 are opened by etching at least a portion of the second portions 12, 12 of the conductive material 6 and the third portions 10, 10 of the conductive material 6 utilizing an aperture 18 in a mask, producing the wordlines 2. However, the mask used to etch the wordlines 2 is complicated and contributes to the complexity of forming the wordlines 2. FIGS. 2 and 3 illustrate six wordlines 2 that are substantially “L-shaped.” To connect the wordlines 2, the contact landing pads 14 and contacts 16 are formed at the opened ends of the wordlines 2 by conventional techniques. While the contact landing pads 14 and contacts 16 are aligned at the top of the memory cell, the contact landing pads 14 and contacts 16 become more staggered when located in proximity to slot or drain contacts. Shorting of the resulting wordlines 2 is also common.
It would be desirable to be able to form and provide contacts to conductive lines, such as access lines (e.g., wordlines) without utilizing the shark jaw layout illustrated in FIGS. 1-3, which would enable easier printing of the wordlines.